Today, alongside the rocky iOS 10 rollout, Watch OS 3 was released. This new version of software brings a laundry list of new features to the Apple Watch, such as the new Application dock, Control Center replacing Glances, an SOS mode and much more.
Another standout feature found in Watch OS 3 is Auto Unlock, which unlocks your Mac when you're close to it.
A new-ish Mac. Auto Unlock only works with Macs from 2013 and newer. Earlier Macs lack Bluetooth 4.0, which is required for Auto Unlock to work. You will also need to have MacOS Sierra installed.
A Mac running macOS Sierra. The public release date for the Sierra update is September 20, but if you can't wait until then, you can download the beta from beta.apple.com/profile. All it requires is a free developer account. It will give you a redemption code to use in the Mac App Store, where you can download and install the beta.
An Apple Watch running watchOS 3. Your Apple Watch will need to be updated to watchOS 3 and secured with a passcode. To setup a passcode, open the Watch app on iOS and select Passcode under My Watch. Tap Turn Passcode On and, on your Apple Watch, enter a four-digit code. Enter the same code once more to confirm.
How to turn on Auto Unlock
While the feature is very straightforward and works with practically zero effort, the setup isn't quite so obvious.
(Searching through the Watch app on iOS won't get you very far. There is no mention of Auto Unlock anywhere in the app. That's because the feature has to be enabled from the Mac on which you want to use Auto Unlock.)
To enable it, go to System Preferences > Security & Privacy and tick the box to the left of Allow your Apple Watch to unlock your Mac. You will be prompted to enter your Mac's admin password. After you enter your password, you may also be prompted to enter the passcode on your Apple Watch. Once you do, the feature will be fully enabled.
How to use Auto Unlock
Now, whenever your Apple Watch is within a few feet -- or about 1 meter -- of your Mac, the Mac will automatically unlock, rather than waiting for you to type in your password. In my experience, this process takes 1 to 3 seconds.
If you happen to take off your Apple Watch, it will not unlock the Mac when you wake it from sleep. You will first need to put the Apple Watch back on your wrist, enter the passcode, then wake your Mac.
Also, Auto Unlock will not work after powering down or rebooting the Mac. After being shut down, you will need to manually enter your password on the computer, similar to having to enter your password or passcode on the iPhone before you can use Touch ID after a restart.
Finally, Auto Unlock will not automatically lock your Mac if you walk away like some third-party versions of this feature, such as MacID. Auto Unlock only works for unlocking your Mac.